Interconnected computers forming networks may have large repositories of data that can be mined for useful information. Although many examples exist, one common example is the Internet, with its decentralized structure of independent hosts which encourages rich exchanges of enormous amounts of data. However, mining useful information from a relatively unstructured source, such as HTML or other type of documents, can be difficult. Locating and identifying relevant information is typically not easy as the largely unstructured nature of the documents does not generally break out the information in the documents by type, value, purpose, etc. As the amount of data grows and the update cycle shortens, extracting desired information from such data becomes increasingly complex.